Questions tagged [problems]

Chess problems consist of a board position and a task. Most ask for a line of play that mates black in a set amount of moves, or a combination that results in a winning position. Many other types exist, including, but not limited to, construction tasks for various positions and proof games that have numerous goals, selfmates, helpmates, and retrograde analysis. Tournaments and championships exist for composing of original problems and for speed-solving.

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2
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1answer
70 views

Help needed with a problem

On an empty board, how can you place a White king, two White, rooks, and a Black king so that White can give mate in 4 ways from that position?
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The quickest selfmate in 1

How quickly can a legal game reach a position where one side must give checkmate? This is in effect Evergalo's reading (see his (now deleted) answer) of Rewan Demontay's Question 33154; that question ...
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What is the fastest way to reach a position in which one side is forced to choose between checkmate and stalemate?

I had an interesting idea recently. While there are many proof games ending in checkmate or stalemate, why not both, I thought. So, thus I wondered, what is the fastest way to reach a position in ...
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How to solve this puzzle of Martin Gardner?

Martin Gardner mentioned the following "chess" problem in his column, Mathematical Games, for Scientific American (he got it from Smullyan, who learned about it from a high school math ...
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2answers
125 views

How many moves needed to reach this position?

"Homebase" is where all the surviving pieces are apparently on their starting squares. Here is a very easy new example proof game: can you find the unique shortest game that leads to this ...
9
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1answer
870 views

From Mate-in-3 to Mate-in-1

Here is my new problem in 3 steps - the key designates here the piece that moves first in the solution. An other way to reach a mate in one I hope you'll enjoy... [Title "From Mate in 3 to ...
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1answer
99 views

Fastest way to get both kings to the other side of the board?

Say that both players collaborate to get White's king to the eighth rank and Black's king to the first. What's the shortest sequence of moves that achieves this?
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Another Unusual Mate in One

Here is another mate-in-one of my own i.e. a not quite usual one... [title "Mate in one"] [FEN "3b4/R3P3/2kPR1n1/P1p1n3/4K1p1/2Nr4/5p2/1b6 w KQkq - 0 1"] Imagine, you ...
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1answer
135 views

Puzzle - Mate in 5 - #001

I've been writing some chess puzzles lately and I thought I would post some of them up here. I'm quite fond of this one so I thought I would share. I traditionally am not a fan of problems that are a &...
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1answer
394 views

Mate in One the Missing King

The post "A mysterious mate in one" made me think of one of my last problems which is also a Mate-in-One with no black King: [Title "White to move and mate in one"] [FEN &...
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1answer
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Timeline of key historical changes to FIDE Laws & WFCC Codex?

A well-answered question here: FIDE Laws of Chess pre-2017 asks for locations of historical sets of FIDE Laws. I am asking for something which partially builds on that. Is there a timeline of "...
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A mysterious mate in one

Here's a question that's a little off the usual format, but problem questions like this have been done before and are on topic, so here we go! Question: Can you find the mysterious mate in one? The ...
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A position with a choice between checkmate and perpetual check

For some odd reason I'm searching for a game, or rather a position, where one player can force a win via checkmate (can be check in n, where n is any number), but they can also force a draw via ...
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1answer
160 views

What is the shortest possible legal game where there are 6 pawns on the a-file or h-file?

I was recently reading a post on this forum which said that there must be 15 captured pieces in order for there to be 6 pawns on the a-file or h-file. That got me thinking how complicated that would ...
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How long can a player hold off a draw by the 50-move rule?

Going by rules strictly about the board state, how long can a player theoretically hold off a draw by the 50-move rule? White will play as long as possible, and not want to lose. Black will claim a ...
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How many times can the king and its surrounding squares be attacked?

In a legal position, how many times can the king and its surrounding squares be attacked? There is a total of 9 possible squares to be attacked-the square the king is on and the eight squares ...
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32 pieces protected once: How many moves?

From the orthodox starting position, how many moves will you need to have the 32 pieces protected exactly once? (The answer is astonishingly low.)
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1answer
202 views

Shortest game controlling a single square 16 times?

Does someone know the shortest orthodox chess game such that a single square is directly controlled 16 times? After 1. Nf3 for instance, the square d2 is controlled 5 times. And 2. ... Qa5 pushes the ...
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Retrograde problem websites

I am looking for a good chess website about retrograde analysis problems, but after a few searches, I haven't found anything. Are there any websites that you can recommend?
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Where are the non captured Black pieces?

[FEN "8/8/8/8/8/PP4PP/2PPPP2/NNBQKBRR w - - 0 1"] Here is a problem from my blog once more. This is the position after White's 14th move. Seven Black pieces were captured during the game ...
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1answer
143 views

Which White piece moved only once?

Here is a chess problem that uses retrograde analysis. I’ve also posted it on the “France-Echecs” chess forum, which is in French of course, and on my blog. [FEN "3qk3/3pp3/8/8/8/3PP3/1PP2PP1/...
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Systematic ways to approach more difficult problems

As I’m done solving easy puzzles (1000–1500), I decided to try some 1700 puzzles, but I’m finding it very hard to solve them as there are no obvious checks, captures and threats. Also, most of the ...
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Maximum number of knights populating a chess board so that no knights are attacking one another

The 8 queen's puzzle is a well-known puzzle involving placing 8 queens on a chessboard so that no queen attacks another queen. It is more or less obvious that 8 is the maximum number of queens that ...
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Chess problem by A. G. Kopnin - Russian notation explanation needed

[Title "Alexey Grigorievich Kopnin - mate in two - 1948"] [FEN "nR1rB3/2PPPN2/bbk1N3/1p2p3/1p2P1nq/1K1Pp3/7B/8 w - - 0 1"] (source) In this problem, it’s white to move and mate in ...
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1answer
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Pinning Combination

There are are four types of pins. Absolute Pin-A piece is pinned to the king and cannot move due to the resulting illegal check. Partial Pin-A piece is pinned to the king and can move along pinning ...
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1answer
268 views

Castling vertically problem

I've once saw a joke chess study about castling vertically. However, I have forgotten who has composed it. I remember that in the positions, all the pawns were locked, but not much else. Does anybody ...
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1answer
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Forced mate: 2 queens vs king

On the board, there are 2 queens (of the same color) placed on random squares. The opposing side has only a king, placed on a random square (and not in check). There obviously exists a mating sequence....
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1answer
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What is the maximum number of checked squares on a board that delivers checkmate without a draw?

I’ve long dreamt of delivering a “super checkmate”. Imagine that as his dying wish, when in checkmate, the king can magically transport himself to any open square on the board. What is the board ...
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1answer
496 views

What is the longest checkmate problem a human has composed?

Well, I looked at some long checkmates, and I wonder, what is the longest checkmate a human has composed?
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1answer
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Which legal position has the smallest number of moves in a “forced loop”?

Consider this (illegal) position. [FEN "5n1k/3p1p1p/3PpPpP/4P1P1/1p1p4/pPpPp3/P1P1P3/K1N5 w - - 0 1"] If we do not consider the position's illegality, and the fact that it is clearly ...
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0answers
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What is the theoretical maximal total of material for the insufficient material draw? [duplicate]

The insufficient mating material rule says that the game is immediately declared a draw if there is no way to end the game in checkmate. This usually happens in KB vs K or KN vs K endgames. However, ...
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2answers
211 views

Infinite sequence of consecutive checks allowing more pieces (say 9+ queens)

This is a task related to this question: Theoretical limit for the number of consecutive checks?. By a sequence of consecutive check, what we mean is white giving check, black replying with a check, ...
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1answer
279 views

How much material is needed to force the capture of a lone queen (for example in horde chess)?

In horde chess, the following starting position is used: [FEN "rnbqkbnr/pppppppp/8/1PP2PP1/PPPPPPPP/PPPPPPPP/PPPPPPPP/PPPPPPPP w - - 0 1"] The goal of White is to checkmate Black; the goal ...
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1answer
137 views

Calculating the precise number of combinations of possible moves from a given position

I was surprised Bobby Fischer couldn't find a mate in 3 within 30 minutes in this problem by Pal Benko. This made me wonder-how many actual moves are possible with so few pieces left in only 3 moves? [...
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3answers
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Can White defend and possibly win?

[FEN "1nkr2nr/pppp2pp/2b2p2/3q4/3P4/1NQ5/P1P2PPP/R1B1R1K1 w KQkq - 0 1"] Can White possibly win in this position and avoid a queen mate on g2?
29
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1answer
2k views

When was it possible for a player's king to be attacked by 3 of the opponent's pieces?

According to the current FIDE Laws of Chess: 3.9.1 The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to ...
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1answer
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What’s the difference between Partial Retrograde Analysis and Retro Strategy?

What’s the difference between Partial Retrograde Analysis (PRA) and Retro Strategy (RS) which are different ways of interpreting retrograde analysis chess problems?
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1answer
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Maximum number of quiet moves in a position

The question of how many captures a position can have has been asked in the past: Maximum number of captures in a position Without captures, and without promotion, which I define as “quiet” moves, ...
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1answer
450 views

How many queens can be on the board without neither forced mate nor forced stalemate (53?)?

I was wondering how many queens can be put on boards without the position being a forced checkmate or a forced stalemate. The best I came up with is 53 this position. [FEN "QQQQQRK1/QQQQQPr1/...
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0answers
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How are ratings determined for training puzzles on lichess.org? [duplicate]

On lichess.org, how are the ratings for the tactical puzzles computed? I am trying to understand how some puzzles I find challenging are as low as the 1400s, while others that seem obvious are at ...
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Why is Ne2 better than Nf3?

I played Nf3 for attacking on king side which is about to castle having some plans to make a battery in future after castling but I feel Ne2 is making a block for Re1 at some point. Any suggestions? [...
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1answer
319 views

Positions that stump engines

Chess engines are so strong that it is becoming increasingly hard to find positions that they are demonstrably evaluating incorrectly. I'm interested in collecting examples—if there are any&...
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2answers
533 views

Which piece combinations can mate a lone king without being aided by the attacking king?

Clearly not a practical question since the king can and should be used in the endgame, but I was curious if anyone has done a comprehensive analysis of which combinations of pieces (including some ...
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1answer
230 views

What is the fastest possible stalemate by castling?

It is known what the fastest stalemate is. But what but is the fastest possible stalemate in which castling must be the last move? 33 plies is my best result so far. [FEN ""] 1. e4 h5 2. ...
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1answer
268 views

Gyula Breyer joke composition cooked?

I recently bought the delightful book Outrageous Chess Problems by Burt Hochberg, which among other things contains some interesting joke compositions. I have a question about Problem 102 (diagrammed ...
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2answers
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What moves solve this mate in 2?

It’s White to move and mate in 2 moves. [FEN "7r/1p3Q1p/2q5/3bk3/1Q2p3/2P5/r2P2PP/2KR4 w - - 0 1"]
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4answers
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How can I prevent checkmate in this position?

It is White's turn to move. How can White avoid a checkmate? [FEN "8/1kpP2q1/1p2P1p1/1P3pP1/5p1K/5P2/6P1/R7 w - - 0 1"]
11
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3answers
640 views

Outside-the-box mate-in-one challenge

I've received an (I would say impossible) mate-in-one challenge and I have already checked all movements, but couldn't solve it yet. It came from a trustable source and they say you need to think ...
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2answers
353 views

Challenge: Create the longest set of moves where the game is able to be perfectly reproduced from only the current board state and move number

The challenge is to create the longest list of half moves whereby an AI could re-create that list of moves perfectly, only given the ending board state and the number of moves. As example I will first ...
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1answer
429 views

Problem with a shorter solution

I'm looking at this problem. [Title "White to move. Mate in three"] [StartFlipped "0"] [fen "5rb1/1p1P1pbr/1p5p/5N/PP2k/1Np3QB/6K/8 b - - 0 1"] It requires white to mate in three. The accepted ...